My MySQL keep shutdown automatically with this error report:

200405 23:31:39 [Warning] Using unique option prefix myisam-recover instead of myisam-recover-options is deprecated and will be removed in a future release. Please use the full name instead.
200405 23:31:39 [Note] Plugin 'FEDERATED' is disabled.
200405 23:31:39 InnoDB: The InnoDB memory heap is disabled
200405 23:31:39 InnoDB: Mutexes and rw_locks use GCC atomic builtins
200405 23:31:39 InnoDB: Compressed tables use zlib 1.2.8
200405 23:31:39 InnoDB: Using Linux native AIO
200405 23:31:39 InnoDB: Initializing buffer pool, size = 128.0M
200405 23:31:39 InnoDB: Completed initialization of buffer pool
200405 23:31:39 InnoDB: highest supported file format is Barracuda.
200405 23:31:39  InnoDB: Waiting for the background threads to start
200405 23:31:40 InnoDB: 5.5.62 started; log sequence number 14465811850
200405 23:31:40 [ERROR] /usr/sbin/mysqld: unknown variable 'set-variable=key_buffer_size=32M'
200405 23:31:40 [ERROR] Aborting

200405 23:31:40  InnoDB: Starting shutdown...
200405 23:31:41  InnoDB: Shutdown completed; log sequence number 14465811850
200405 23:31:41 [Note] /usr/sbin/mysqld: Shutdown complete

When I try to log into MySQL it says:

DBI connect failed : Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

I try to open /var/run/mysqld/mysqld.sock and can not found mysqld.sock

This happened after I tried to set key_buffer_size=32M by using webmin.

How to make it stop trying to set the key_buffer_size?

  • What version of MySQL? Of the configuration package?
    – Rick James
    Apr 14, 2020 at 3:23
  • It seems that MySQL config in webmin has not been upgraded in at least a decade. Don't depend on it.
    – Rick James
    Apr 14, 2020 at 3:39

2 Answers 2


in the Module Configuration for mysql you find the path to my.cnf

enter image description here

Edit this file and remove the line with key_buffer_size=32M and save it.

And then start the server.

Webmin information on mysql

  • I've remove key_buffer_size from my.cnf but it still wont start, and the error message is still the same
    – Rama Aryo
    Apr 5, 2020 at 18:04
  • is it because the "set-variable=" before key_buffer_size=32M? how to stop mysql from sending this command?
    – Rama Aryo
    Apr 5, 2020 at 18:07
  • mysql start twith the my.cnf file specified.. If you remived the line and save d the file it should noz give the error. How do you put it there in the first place?
    – nbk
    Apr 5, 2020 at 18:13
  • I finally found the problem in my.cnf there's a line like this set-variable=before key_buffer_size=32M I remove all of it, including set-variable. and my database work find Thank you very much for your help
    – Rama Aryo
    Apr 5, 2020 at 18:16
  • good please accept the answer
    – nbk
    Apr 5, 2020 at 18:19

I had the same problem. After I # the variable I got another error of a non existing variable. So I deleted the my.cnf in etc/. I guess this means use default variables. After that all works in good order.

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